Aesthetic relativism is the philosophical view that the judgement of beauty is relative to different individuals and/or cultures and that there are no universal criteria of beauty. For example, in historical terms, the female form as depicted in the Venus of Willendorf and the women in the paintings of Rubens would today be regarded as over-weight, while the slim models on the covers of contemporary fashion magazines would no doubt be regarded in a negative light by our predecessors. In contemporary (cross-cultural) terms, body modification among "primitive" peoples is sometimes regarded as grotesque by Western society.

Aesthetic relativism might be regarded as a sub-set of an overall philosophical relativism, which denies any absolute standards of truth or morality as well as of aesthetic judgement. (A frequently-cited source for philosophical relativism in postmodern theory is a fragment by Nietzsche, entitled "On Truth and Lie in an Extra-Moral Sense.")

Aesthetic relativism is a variety of the philosophy known generally as relativism, which casts doubt on the possibility of direct epistemic access to the "external world", and which therefore rejects the positive claim that statements made about the external world can be known to be objectively true. Other varieties of relativism include cognitive relativism (the general claim that all truth and knowledge is relative) and Ethical Relativism (the claim that moral judgments are relative). Aesthetic and Ethical relativism are sub-categories of Cognitive Relativism. Philosophers who have been influential in relativist thinking include David Hume, particularly his "radical scepticism" as set out in A Treatise of Human Nature; Thomas Kuhn, with regard to the history and philosophy of science, and particularly his work The Structure of Scientific Revolutions; Friedrich Nietzsche, in moral philosophy and epistemology; and Richard Rorty, on the contingency of language.

Philosophers who have given influential objectivist accounts include Plato, and in particular his Theory of the Forms; Immanuel Kant, who argued that the judgment of beauty, despite being subjective, is a universally practiced function of the mind; Noam Chomsky, whose "nativist" theory of linguistics argues for a universal grammar (i.e., that language is not as contingent as relativists have argued that it is).

The most prominent philosophical opponent of aesthetic relativism was Immanuel Kant, who argued that the judgment of beauty, while subjective, is universal.

Recent experiments in psychology seem to contradict aesthetic relativism. In studies of facial attractiveness there seems to be wide cross-cultural agreement as to what constitutes beauty in the human face. Whether this is down to symmetry or averageness is a matter of disagreement. Studies with infants, presumably too young to have been socialised, have shown that they consistently prefer the kinds of faces which adults judge to be "attractive" (Van Duuren, Kendell-Scott, & Stark, 2003; Langlois, Ritter, Roggman, & Vaughn, 1991; Samuels, Butterworth, Roberts, Grauper, & Hole, 1994; Samuels & Ewy, 1985; Slater, Bremner, Johnson, Sherwood, Hayes, & Brown, 2000) The judgement of beauty may be hard-wired in human beings, possibly fulfilling an evolutionary role.

At the same time, the dominant media-generated image in terms of facial structure, body shape and hair colour is that associated with northern Europeans. Furthermore, it should be noted that the fashion for darker skin among white people is of relatively recent origin, coinciding with the fashion among the upper classes for sun-holidays in the early twentieth century.

In some cases, common sense may appear to suggest that aesthetic relativism is false. There is widespread agreement—at least among the "informed" and "educated" public—as to the aesthetic value of individual works of architecture, painting, music, etc. The question whether or not such agreement pre-exists social conditioning is an ongoing one, and mirrors the broader nature versus nurture debate within the social sciences, and within science and philosophy in general. (For example, an informed and educated public might have been informed and educated in different ways, and their tastes might then have been quite divergent.) The extent to which taste might be explained in fundamentally sociological as distinct from aesthetic terms, is a matter of ongoing debate.

Aesthetic relativism is common in the social sciences and in feminist thought. "Beauty" is regarded as a social construct rather than as fulfilling a natural function (e.g. in terms of sexual attraction and reproduction). For example, the tendency to cultural tolerance of signs of ageing such as gray hair and wrinkled skin in men, to a greater extent than in women, is seen by some as culturally determined. This view, however, ignores the fact that the age-span for reproduction is markedly different in the two sexes, and consequently the criteria for aesthetic (sexual) attraction may be correspondingly different. (On the other hand, men as well as women are under increasing pressure to conform to what some might argue is a media-determined ideal of a youthful appearance.)

On the relationship between aesthetics, sexual attraction and reproduction see Arthur Schopenhauer "On the Metaphysics of the Love of the Sexes", in his major work The World as Will and Representation / die Welt als Wille und Vorstellung. For Schopenhauer, the criteria for sexual attraction are (in women from the perspective of men) beauty, youth and health; and (in men from the perspective of women) status, strength and wealth. This is because these are believed to be the optimal conditions for the reproduction of the species: the well-being of the potential offspring is always the key concern, although one or both of the partners may be quite unconscious of this.